Industrial and papermakers&#39; felt and method of producing the same



March 4, 1952 P.T.GATES INDUSTRIAL AND PAPERMAKERS' FELT AND METHOD OFPRODUCING THE SAME Filed Jan. 16, 1948 INVENTOR FERENALT EIATEEI BY flWW ATTORNEY Patented Mar. 4, 1952 INDUSTRIAL AND 'PAPERMAKERS' FELT ANDV METHODOF-PRODUCIN, G'THE SAME Percivahfl. Gates,: Suffield, C onnassignor-ltom Drycor FeltCompan y Belleville, N. J.,la corpo-vl ration.of NewJersel'a.

Application Januaryl16, 1948, SeriaLNo. 2,714 I Y 14t,Claims... 01..281-722.)

.Ihe; presentimventionzrelates tozindustrial and paper makers; felts andmethodof producing; the: same and is;.direc:ted particularly to animproved;

machine rduc s =.as--; u pa er; zra e a dr asbestos cement,prod-natal;.millboardl gaskets boardi, ,sbestos t-papens andI :the alike. Such feltsproduced. in; endlesstbelt; form :orproducedas a fla;fabricswhioh-ssisathereafter "joined together at;;its.:ends.-ttoriiormanr, endless rbelt, the belt being mountedin the paper? makingmachine:upon SllitablQarOHSw Its-.wprincipal functions; are :topartzafinishlrttorzthe sheet of paper orothertmaaterialcarried.lonrthes; felt-,- and to ,remove water; from it": bydrainage of the water through. the;

feltalv this. ywaterr; removal z. being accomplished throughtheacooperation-lf press-trolls, suction boxeslandithe like, The papermakers felt thus constitutes amechanical;p rt oft-the papernmae chine,in-l-such ,msel .lis subjected Vito friction,

abrasion chemical deterioration, and deterioraa t,

tion'..du toabacterial. molds, mildews, .fu'nguses,

eta:L ,structural Nandgfunctional character-a istics..- are thereforepeculiarly related tomtherequirementslof its .tusewinl .paper machines,as dis tinguished fromiabricsvdesignedifor other uses,

slichilas'clothing, carpets. blankets,; and"the like.

'I'hjeinvention is concerned with paper makersf;

felts.jof theilsowalled needle'd type, asdistzlosed fort-finstancaaingthe .Reissue Patent No; 213390; reissued August .26, 1941i ZtogPatrick'Walsh and Percival TJGa'te'S' for Industrialand Papers makersi Felts.Needled paper makers .felt' 'Jconteaze'led to l1 produce ea .rnapped:surface.

thes

invention is toaemDlQy incorporaterisuch-kfieeces. inthejfel'tibl aninter locking=1rofthe*fibers-"- brought about" by ""the needlin'gprocessg-ms distin'guished -from certain 65 produced byj flee'cesof.fibre material; needled into uthe'ibase g'fabric; asdistinguishedfromhthey typg'gof jeltfialso used in-"paper"manufacture;-conSisting ofa" woven *fabric;usually wool; which bj'ected tota-fullin'gprocess toshrink and compact) the fabridand l is then- :brushedor natural fibers such as wool,

2 known felts hin-whiphuthe; synthetic fibers; are combined with Y wooland spunlinto yarns, which;

in turn-are woveninto aielt fabric. v

The, synthetic fiber materialy best: suited to 1 carrying; out theinventiomhasa smooth-land;

slippery surface; so-that dirt and othertforeign; substancesapassinggthrough; the felt :With ethe drainage; wateimdo not adhereto-the fibers,,as they do in the case of certainanaturali-fibersg such as 1 wool;which have a scaly; surface and make the felt susceptibleto filling ;up1= after a relatiyely short use -.in the lpaper:machine,with consequentdeterioration in tthe uniform l qualityof.v the products produced on-thefelt. Another; desired characteristic .of the a synthetic-fibers is thatit should not have any appreciable fullingiz quality, as distinguishedlfromwcertains natural fibers, such astwool which ,continue to; fulliwhile in use on thehpapermachinel-withwthe result that: the felts.become progressively; more dense, and. in doing tend to fill upuwith Jdirt, and other foreign materials. Aw-furthenrdesired characteristiciisthat the synthetic fiberwmaterial behighly resistanttofrictionandabrasion, and to chemical deterioration and deteriorationdue. to bacterial molds,- mildews, funguses, etc.

A suitable synthetic-fiber material having, the. desired characteristicsfor carrying out the in: vention is the polyamidv known asnylon. AOther. suitable. materials are. synthetics such. as rayon.- fiber, milkproducts like casein fiber, and glass; fiber. Itislproposed,faccordingwto the invention; to. use synthetic j fibermmaterial, for instance nylon, either alone, or in any desiredpercentages combination with Iothernsynthetic Lfiber,,, or with cotton,ramie, hemp. asbestos;..etc.. Withthe above and other objectsinQVieWL-an. embodiment jof' the invention isshown innthe accompanying,drawing, and this embodiment will be hereinafter more fullydescribedwitlifrefrr erence thereto vand'thelinvention willbefinally;pointed out in the claims.

In thedrawings': Fig; 1 isja plan. view .of, a'paperlmakersfifelt. inthe form ofan endlessbelt,.'according toflth. invention, a portion ofEthel woven. abase "being" shown without fibers attached thereto. Fig.2is a transverse sectionaLview along the; line 2--2 of Figil; Fig.3 isan enlarged transverse sectional view? showing a portion'of the feltgthepronouncelyz; heavy "lines; showing? the characteristic" inter-"1 lockedposition uncertain 'of theisynthetic fibers; Rc eferringtov thedrawings, the paper;makersi" feltfi according to the illustratedexemplaryem vmaterial into and through the woven base.

out the additionof'fibrous material.

bodiment of the invention, is in the form of an endless belt comprisinga woven base consisting of warp threads or cords l and weft threads orcords l l and having a relatively open mesh. The woven base merely formsa support for the fibrous material needled into it and does not have itsown fibers brushed into a nap, so that it is not subject to the abrasiveaction the surface of the felt is called upon to resist. It may be sodesigned, and constructed of such material as to give it maximumlongitudinal and lateral tensile strength without having to build intoit any abrasive resistance. This makes possible the use of relativelyfine yarns of cotton or other suitable material, which impart a minimumof felt marking to the material being made on the felt.

The fibrous material 12 which makes up the front and back surfaces ofthe felt is secured thereto by needling, as will be hereinafter morefully pointed out, the needling process fundamentally consisting inapplying one or more bats,

layers, or pile fleeces of fibrous material to the front and back of thewoven base and progressively needling it into and through the base, the

material being gradually moved beneath vertical- 1y reciprocatingneedles which force the fibrous In practice one or more layers orfleeces are needled at each side of the felt.

According to the invention the fiber material of at least one of thefleeces consists wholl or in part of synthetic fibers, as for instancenylon. The needling process is such that when such synthetic fibers areprovided in at least one of the fleeces, parts of these fibers will becarried -into the fleeces at both sides of the felt, and will thereforecooperate in the structure to bring about the functional and structuraladvantages characteristic of the needled synthetic fibers.

Also, any or all of the fleeces may consist wholly or in part ofsynthetic fibers. The synthetic fibers may be blended or mixed in anysuitable percentage with natural fibers such as wool, cotton, ramie,hemp, asbestos, or the like, and may also be mixed or blended with othersynthetic fibres. Thus the entire front and back of the felt may beneedled with fleeces consisting of 100 per cent synthetic fibers, forinstance nylon, the front and back may be needled wth fleeces consistingof a blend of synthetic fibers andnatural fibers, as for instance nylonand wool, and the felt may have the front fleece formed of naturalfibers and the back fleece formed wholly or in part of synthetic fibers.The synthetic fibers may be provided in any desired lengths andthicknesses, and may be either straight, crimped, or curled, and becauseof the controlled manner in which such synthetic fibers are producedthese characteristics may be accurately predetermined. The fleeces arefirst needled into the base fabric in the regular manner, that is, oneor more layers or fleeces are needled at each side of the felt until thedesired amount of fibrous material is attached to the base fabric.Thereupon the felt is subjected to a further needling operation with-This consists in needling the felt from the opposite side from the sidelast fleece-needled, producing an interlocking tuck-in of the fibersfrom one side, and thereupon needling the felt from the same side as thelast fleece-needled side, so that the fibers at this side are also givenan interlocking tuck-in. Thepronounced lines in Fig. 3 show thecharacteristic interlocked arrangement of certain of the syntheticfibers resulting from this I method. This gives an interlocking effectwhich it is not possible to accomplish through the needling in of thefleece alone, and results in cerstain of the fibers extending back andforth one advantages are obtained where the synthetic fibers are blendedwith wool or other natural fibers. The individual nylon fibers are forinstance much stronger than wool fibers and have a smooth and slipperysurface, so that it is possible to interlace these fibers through thefelt several times without breaking to thus interlock the nylon fibersin place and also hold-the wool fibers in place. It is also found thatwith this interlocking method there is a great reduction in the amountof nap or loose hairs in the surface of the felt thus reducingobjectionable shedding.

Since the fleeces are interlocked through the base fabric by theneedling process in a position perpendicular to the base fabric, thefibers of the synthetic and natural materials are in the optimumposition to cushion the base fabric and offer resistance to abrasion. Ithas been found that synthetic fibers, such as nylon, when blended withnatural fibers, such as wool, contribute the following importantqualities to the pile fleeces of the felt.

First, the felthaving synthetic fibers, such as nylon, incorporatedtherein is highly resistant to abrasion. The nylon fibers are muchstronger and resist abrasion much longer than wool fibers, with theresult that as the wool fibers wear off and break off the nylon fiberscome more and more to the surface taking more of the wear and thustending to cover and protect the remaining wool fibers.

Second, the synthetic fibers, for instance nylon, are highly resistantto acid or alkaline conditions and to bacterial mold or mildewdeterioration, so that they remain intact much longer than the naturalfibers and tend to develop a protective covering over the natural fibersthus prolonging to a considerable extent the life of the felt as awhole.

Third, due to the fact that the nylon and other synthetic fibers have asmooth and slippery surface, dirt or foreign substances, passing throughthe felt with the drainage water, do not adhere to them as is the casewith the scaly wool fiber. Thus, the use of synthetic fibers produces afelt which is less susceptible to filling up" and therefore the usefullife of the felt is increased as well as the uniform quality of theproduct produced on the felt. When a felt begins to fill up it begins tolose its draining and water removal properties, it causes a depreciationin the quality of the product being produced on it, and it becomessubject to more and more severe abrasive action. As the filling upcontinues, these three factors become progressively worse until the felteither will not take out enough water to operate successfully, or theproductis not within saleable standards, or the'felt rapidly wears out.By staying clean longer, a felt will produce a more uniform product andproduqm mace-a ar;

sreateremzoouctiombecaus hiewemrshutrdom" foracleanina and changin .l

:grfull while .usewnQ-the aperl.

maintaining the uniformity of the product being manufactured on thefelti'ez I Fifth?" due" to' -the use of- "synthetic fibers-, forinstance nylon, in the fleeces of the felt it is possible to materiallyincrease the amount of water removed, and the speed with which thiswater is removed, from the productbeing produced on the felt. This isdue to the smoothness of the synthetic fibers and their ability to keepthe. fleeces open. This is a highly important quality in the felt,leading to increased speed of production of the paper or other materialbeing produced, and a reduction in the cost of the drying of theproduct, since water not removed from the product by the felt has to beremoved by some other means, usually heat.

What is claimed is:

1. A paper makers felt for supporting and draining, paper makingmaterial, comprising a non-fulled woven base in which the warp and weftstrands have an open weave to provide drainage passages from the front"side to the back side, and nap producing layers of fiber materialrespectively at the front and back sides of said woven base attachedthereto by fibers of said layers needled into and through said base fromone to the other of said layers, at least one of said layers beingcomposed at least in part of non-fulling pliable synthetic fibermaterial, the individual fibers of which are disposed partially at therespective sides of said woven base and partially in the drainagepassages in a direction substantially perpendicular to said woven baseto direct drainage water therethrough.

2. The invention as defined in claim 1, further characterized in thatsaid synthetic fiber material is nylon.

3. A paper makers felt for supporting and draining paper makingmaterial, comprising a non-fulled woven base in which the warp and weftstrands have an open weave to provide drainage passages from the frontside to the back side, and nap producing layers of fiber materialrespectively at the front and back sides of said woven base attachedthereto by fibers of said layers needled into and through said base fromone to the other of said layers, at least one of said layers beingcomposed in part of natural fiber material and in part of nonfullingpliable synthetic fiber material, the individual fibers of which aredisposed partially at the respective sides of said woven base andpartially in the drainage passages in a direction substantiallyperpendicular to said woven base to direct drainage water therethrough.

withiitherresult hatuthel-if ltsl. time 4.=: 3I'li'er invention;asezidefiznecl 1 claim themcharacterized insthatma, i materials wool;

5.:Thezirrinventiontdeflnedeimicla m characterizedsinrthatasaidiV a.ural fib' m; isl'woolland-,saidisynthetic:fibemnateriaagemassagesrfromcthe;frontiside and nap producing layers of fibenspectivelmtatrthe;frdnt randkiback-s-sideszzof ,sai woven: baseattached;theretdbyv-fibers oft.

' lair tron-sub. tantla pc I pendicularito said awovembaseitoed rectg ranaee water ithfirfithfll l he rt 7. The invention as defined in claim 6,further characterized in that said synthetic fiber material is nylon.

8. A paper makers felt for supporting and draining paper makingmaterial, comprising a non-fulled woven base in which the warp and weftstrands have an open weave to provide drainage passages from the frontside to the back side, and nap producing layers of fiber materialrespectively at the front and back sides of said woven base attachedthereto by fibers of said layers needled into and through said base fromone to the other of said layers, all of said layers being composed atleast in part of non-fulling pliable synthetic fiber material, theindividual fibers of which are disposed partially at the respectivesides of said woven base and partially in the drainage passages in adirection substantially perpendicular to said woven base to directdrainage water therethrough.

9. The invention as defined in claim 8, further characterized in thatsaid synthetic fiber material is nylon.

10. A paper makers felt for supporting and draining paper makingmaterial, comprising a non-fulled woven base in which the warp and weftstrands have an open weave to provide drainage passages from the frontside to the back side, and nap producing layers of fiber materialrespectively at the front and back sides of said woven base attachedthereto by fibers of said layers needled into and through said base fromone to the other of said layers, all of said layers being composedwholly of non-fulling pliable synthetic fiber material, the individualfibers of which are disposed partially at the respective sides of saidwoven base and partially in the drainage passages in a directionsubstantially perpendicular to said woven base to direct drainage watertherethrough.

11. The invention as defined in claim 10, further characterized in thatsaid synthetic fiber material is nylon.

12. A paper makers felt for supporting and draining paper makingmaterial, comprising a non-fulled woven base in which the warp and weftstrands have an open weave to provide drainage passages from the frontside to the back side, and nap producing layers of fiber materialrespectively at the front and back sides of said woven base attachedthereto by fibers thereof needled into and through said base from one tothe other of said layers, at least one of said layers being composed atleast in part of non-fulling pliable pendicular to said woven base todirect drainage watentherethrough, at least some of said syntheticfibers being directed back and forth through said vwoven base and havingtheir ends directed inwardly toward said woven base.

13. The invention as defined in claim 12, further' characterized in thatsaid synthetic fiber woven fabric base in which the Warp and weftstrands have an open weave to provide drainage passages from the upperto the lower side, needling nap producing layers of fiber materialrespectively at the front and back sides of 'saidwoven base to causefibers of said layers to be; needled into and through said base from oneto p the other of said layers, and further needling without the additionof fiber material at each side of said felt to cause certain of saidfibers previously needled in one direction to be carried through thefelt in the opposite direction, and to cause loose ends of certain ofsaid fibers to be inserted into the nap at each side of said felt.

PERCIVAL T. GATES.

' REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 7 Number Name Date Re.21,890 Walsh et al. Aug. 26,1941 1,442,327 DeLong Jan. 16, 1923 2,331,321 Heaton Oct. 12, 19432,423,828 Chagnon July 15, 1947 FOREIGN PATENTS Number Country Date869,766 France Feb. 16, 1942

